This is an area that I know little about, but I have had good experince with d aspartic acid. I would reseach that if you are interested in natural test boosting. It also has a other benefits that make it worth taking, on or off cycle. Be aware though, natural test boosters may be helpful for recovering from a cycle, and possibly for general health purposes, but it isn't going to get you big. At best, the rise in test will be minimal.